1. Field of Invention:
This invention relates to doors and particularly to one-piece type door and especially to an overhead tilt door.
2. Prior Disclosures:
Overhead doors used to close the doorway of structures ranging from one vehicle garages to airplane hangars have been in use for sometime. One such overhead door assembly construction is shown in U.S. Pat. No. 2,141,515. The door construction disclosed therein includes a system of vertical and horizontal tracks with the vertical tracks mounted adjacent the sides of the door frame and the horizontal tracks extending inwardly from the door frame. Rollers are provided at the upper ends of the door for engaging with the tracks. Another pair of rollers is mounted on the door below the center of mass thereof, but above the bottom of the door for engagement with the vertical tracks. The door is thus adapted to be swung outwardly and raised from a closed vertical position to a substantially horizontal overhead position. Counterweights act against the door below the center of mass at the points where the lower pair of rollers are mounted. Various other type overhead tilt doors are shown in U.S. Pat. Nos. 663,989; 1,476,097; 2,054,735 and 2,323,585.